You could try an arcane giant. The dynamics are a bit different, you're likely to get an 8/8 out for 5-6 mana instead of a 6/6 out for 3 mana, but probably around the same turn. I'm not saying it's a perfect sub, but it's easy to acquire.

You had a free discounted spell off Preparation and chose to use it on Backstab instead of a free Sap to allow the use of Cold Blood afterwards. After that, you had the chance of making a 6/6 VanCleef after dropping the Pillager + Coldblood and instead chose to end the turn. My eyes bleed.

On second match, you dagger'd up and Prep'd a Deadly Poison and instead could've used an Eviscerate to drop a 6/6 VanCleef that turn.